Date: Thu, 19 May 2005 15:36:31 -0600

Author: Jerry DiMarco

Subject: Re: An invisible wall created by static electricity?

Post:

This a pretty interesting phenomenon. It is not the sort of topic we
usually discuss though we've been known to get off on tangents
occasionally. Unfortunately it is difficult to speculate about the cause
because there are too many unknowns. For instance, how many rollers were
there, what were they made of and what effect did they have on the
sheet? How extensive was the field and what was its shape? What exactly
was he feeling? Since there were moving charges, could there have been a
magnetic field present (water is diamagnetic which means it is repelled by
both poles of a magnet)?
I followed a few of the links trying to find out more, and it appears
the best possibility is the Static Planet website that 3M is going to
produce. Until that premiers and I read what David Swenson knows about the
incident and the solution he crafted, it probably wouldn't be productive to
spend any more time on it. Sure would like to get to the bottom of it
though - it would make an interesting demo. Perhaps you can find the
answers to your questions in the reference links given on the demo pages
you cited...

Jerry

At 07:55 AM 5/15/2005, you wrote:
> Hello. I've written a few people about this question
>but I thought this list might be a good source of
>information since my question references some PIRA
>experiments.
> I copied below a post to sci.astro on a strange
>phenomenon involved with high-voltage static
>electricity. It concerns the creation of an "invisible
>wall" due to electrostatic charge from a large sheet
>of polypropelene film moving at high speed at a 3M
>plant:
>
>David Swenson's electrostatic "invisible wall".
>http://amasci.com/weird/unusual/e-wall.html
>
>A perhaps related phenomenon is illustrated by this experiment on Hero's
>Fountain:
>
>Expt 013 -- Hero's Fountain.
>http://chemmovies.unl.edu/chemistry/beckerdemos/BD013.html
>
>Here, a electrostatically charged balloon held near a
>Hero's Fountain causes the fountain to dissipate. See the video at the
>link in step #4 in the Procedure section.
>
>In the post to sci.astro, I suggest the effect at the
>3M plant was due to the effect electrostatic charge
>has on polar molecules such as water. Dave Swenson an
>expert on electrostatic discharge estimated the
>voltage produced was in the megavolt range. What would
>really seal this as the cause would be to see if the
>same "invisible wall" was observed to effect materials
>composed of non-polar molecules.
>I would like to be able to estimate the possible force
>produced on a polar molecule such as water by an
>electrostatic charge and what would be the magnitude
>of the electrostatic voltage created by a Van de
>Graaff generator dependent on its dimensions.
> Do you know of any such formulas for this? Also, are
>you aware of any experiments with megavolt-scale
>electrostatic generators demonstrating this effect on
>polar substances?
> In the 3M plant phenomenon, there appears to be a
>*repulsive* effect.
>I presume there is also a repulsive effect in the
>Here's Fountain experiment as well since in the video
>the fountain is made to stop when the charged balloon
>is brought close to the stream.
> But this page says a stream of falling water will be
>*attracted* to a charged balloon:
>
>Lesson 1: Charge and Charge Interactions
>Polarization.
>http://www.glenbrook.k12.il.us­/gbssci/phys/Class/estatics/u8­l1e.html
>
> Also curious is what this page on this experiment says of it:
>
>J4-11: POLAR AND NONPOLAR LIQUIDS.
>"NOTE: Although the demonstration apparently works as
>predicted, this demonstration does not work according to theory, and
>should probably not be done and explained in the traditional manner."
>http://www.physics.umd.edu/lec­dem/services/demos/demosj4/j4-­11.htm
>
>
> And in this video version of the moving lumber experiment, the lumber
>is *attracted* to the charged rod whether it is charged positive or
>negative:
>
>Question #131
>http://www.physics.umd.edu/lec­dem/outreach/QOTW/arch7/q131.h­tm
>
>
>
> So it is indeed puzzling how you could have a repulsive effect in the 3M
> plant case.
>
>
> Thank You,
>
> Bob Clark

From frysingerj@cofc.edu Thu May 19 18:02:25 2005

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